: This is a proposal for a meeting to held in San Diego, CA, from October 7-10, 1999, to address new information relevant to the Pathology of the Surfactant of the Mature Lung. This meeting will follow, by over 4 years, an initial highly successful meeting on this subject. As before, the goals are to bring together scientists working in a variety of disciplines, including molecular and cell biology, physiology, neonatology, anesthesiology, and internal medicine, for discussions that will stimulate growth of knowledge in the area of surfactant research. Since the prior meeting, new developments have occurred in multiple areas that are identified in the application. The meeting's goals are: (a) to present a summary of new developments in laboratory and clinical investigations; (b) facilitate communications between investigators in various fields of surfactant research; and (c) encourage investigators at the junior faculty level and from under-represented minorities by providing a forum in which they can present their work.